JAXB- @XmlMixed usage for reading @XmlValue and @XmlElement

Question

I saw a similar question being posted here, yet it did not help me solve the problem so I am posting my question here to see if someone can modify my code to make it work.

Question: How to access mixed content String value and save it in setPhrase(String value) method?

caption.xml:

<?xml version="1.0" encoding="UTF-8"?>
<tt xmlns="link1" xmlns:prefix2="link2" prefix1:att1="att1">
    <head>
        <styling>
            <style prefix1:att1="att1" prefix2:att2="att2" prefix2:att3="att3" prefix2:att4="att4" />
        </styling>
        <layout />
    </head>
    <body xmlns:prefix3="link3">
        <div prefix1:att1="att1" prefix1:att2="att2">
            <prefix3:info att1="att1" att2="att2" />
            <p att1="att1" att2="att2" att3="att3">
                <prefix3:status att1="att1" att2="att2" />
                Hello World.
            </p>
        </div>
    </body>
</tt>

Caption.java:

package com;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementRef;
import javax.xml.bind.annotation.XmlElementRefs;
import javax.xml.bind.annotation.XmlMixed;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;

@XmlRootElement(name = "p")
@XmlType(propOrder = { "att1", "att2", "att3", "phrase", "subelement"})
public class Caption {
    private String  att1;
    private String  att2;
    private String  att3;
    private String  phrase;
    private Subelement subelement = new Subelement();

   @XmlMixed
   public void setPhrase(String value)
   {
      this.phrase = value;
   }
   public String getPhrase()
   {
      return phrase;
   }

   @XmlElementRefs({@XmlElementRef(name = "subelement", type = Subelement.class)})
   @XmlMixed
   public void setSubelement(Subelement subelement )
   {
      this.subelement = subelement;
   }
   public Subelement getSubelement()
   {
      return subelement;
   }

   @XmlAttribute
   public void setAtt1( String att1 )
   {
      this.att1 = att1;
   }
   public String getAtt1()
   {
      return att1;
   }

   @XmlAttribute
   public void setAtt2( String att2 )
   {
      this.att2 = att2;
   }
   public String getAtt2()
   {
      return att2;
   }

   @XmlAttribute
   public void setAtt3( String att3 )
   {
      this.att3 = att3;
   }
   public String getAtt3()
   {
      return att3;
   }
}

After using JAXB unmarshall and marshall I am able to get everything converted into and object and saved accorderling, except for the actual phrase "Hello World.". I know I must use some sort of @XmlMixed for this complex element but I cannot figure it out.

My current output.xml:

<?xml version="1.0" encoding="UTF-8"?>
<tt xmlns="link1" xmlns:prefix2="link2" prefix1:att1="att1">
    <head>
        <styling>
            <style prefix1:att1="att1" prefix2:att2="att2" prefix2:att3="att3" prefix2:att4="att4" />
        </styling>
        <layout />
    </head>
    <body xmlns:prefix3="link3">
        <div prefix1:att1="att1" prefix1:att2="att2">
            <prefix3:info att1="att1" att2="att2" />
            <p att1="att1" att2="att2" att3="att3">
                <prefix3:status att1="att1" att2="att2" />
            </p>
        </div>
    </body>
</tt>

Desire output.xml: (same as caption.xml)

<?xml version="1.0" encoding="UTF-8"?>
<tt xmlns="link1" xmlns:prefix2="link2" prefix1:att1="att1">
    <head>
        <styling>
            <style prefix1:att1="att1" prefix2:att2="att2" prefix2:att3="att3" prefix2:att4="att4" />
        </styling>
        <layout />
    </head>
    <body xmlns:prefix3="link3">
        <div prefix1:att1="att1" prefix1:att2="att2">
            <prefix3:info att1="att1" att2="att2" />
            <p att1="att1" att2="att2" att3="att3">
                <prefix3:status att1="att1" att2="att2" />
                Hello World.
            </p>
        </div>
    </body>
</tt>

Thanks in advance to any help I may get to access this value and save it in setPhrase(String value) method.

score 18 · Accepted Answer · answered Jun 19 '12 at 10:42

I'll try to answer your question with an example:

input.xml

We will use the following XML document for this example. The root element has mixed content. Having mixed conent means that text nodes can appear mixed in with the elements. Since more than one text node can appear a unary property isn't a good fit.

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <root/>
    Hello
    <root/>
    World
    <root/>
</root>

Demo

The following code will be used in to read in the XML to object form and then write it back to XML.

package forum10940267;

import java.io.File;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Root.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum10940267/input.xml");
        Root root = (Root) unmarshaller.unmarshal(xml);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(root, System.out);
    }

}

USE CASE #1 - One List to Hold Mixed Content

@XmlMixed is most often used to with another annotation, so that the resulting List contains both element and text content. One advantage of this is that order is maintained so that the document can be round tripped.

package forum10940267;

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement
public class Root {

    private List<Object> mixedContent = new ArrayList<Object>();

    @XmlElementRef(name="root", type=Root.class)
    @XmlMixed
    public List<Object> getMixedContent() {
        return mixedContent;
    }

    public void setMixedContent(List<Object> mixedContent) {
        this.mixedContent = mixedContent;
    }

}

Output

The output matches the input.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<root>
    <root/>
    Hello
    <root/>
    World
    <root/>
</root>

USE CASE #2 - Separate List for Mixed Content

You can can also introduce a separate list property for the text content.

package forum10940267;

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement
public class Root {

    private List<Object> mixedContent = new ArrayList<Object>();
    private List<String> text;

    @XmlElementRef(name="root", type=Root.class)
    public List<Object> getMixedContent() {
        return mixedContent;
    }

    public void setMixedContent(List<Object> mixedContent) {
        this.mixedContent = mixedContent;
    }

    @XmlMixed
    public List<String> getText() {
        return text;
    }

    public void setText(List<String> text) {
        this.text = text;
    }

}

Output

The output no longer matches the input.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<root>
    <root/>
    <root/>
    <root/>

    Hello

    World

</root>

USE CASE #3 - String Property for Text Content

Since text nodes can occur multiple times in mixed content, a non-List property isn't a good fit and it appears as though the @XmlMixed annotation is being ignored.

package forum10940267;

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement
public class Root {

    private List<Object> mixedContent = new ArrayList<Object>();
    private String text;

    @XmlElementRef(name="root", type=Root.class)
    public List<Object> getMixedContent() {
        return mixedContent;
    }

    public void setMixedContent(List<Object> mixedContent) {
        this.mixedContent = mixedContent;
    }

    @XmlMixed
    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }

}

Output

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<root>
    <root/>
    <root/>
    <root/>
</root>

Thanks for your help Blaise. I was able to get it to work. Also do you know a way to make sure the root prefix (prefix1:att1="att1") is the last thing shown? I want it to appear in tt element last, after namespaces (xmlns="link1" xmlns:prefix2="link2"). — abner.ayala, Jun 21 '12 at 18:37

JAXB- @XmlMixed usage for reading @XmlValue and @XmlElement

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